Uryk’s company ‘Evolution E-types’ continues to post new parts they have developed on their Instagram feed. They never make it clear whether they will be made available to the unwashed masses, or whether they are being reserved for the custom cars they are building, but it’s hard to believe they could justify developing most of these parts for a small handful of cars a year.
Their latest post is for a clutch kit they’ve apparently developed. You can clearly see the Sachs name on the disc, but more notably, it includes a ‘roller’ throw-out bearing that is designed to remain concentric with the 1st motion shaft.
Before anyone says this is an answer looking for a question, there was a bad batch of ‘Chindian’ carbon throw-out bearings a few years ago in MG-land, and there were plenty of pissed off people with infant-mortality failures, where the carbon ring quickly broke away from its casing. That would be frustrating enough on a car where you can R&R the clutch in 6-8 hours…but if that occurred in E-type-land, there might be people jumping off buildings.
An OE quality roller bearing with a properly engineered carrier is something I would welcome these days on a car originally equipped with a carbon throw out bearing.
The pilot shaft for the bearing is key. I’d buy a kit next time assuming they make them available. Note that the fingers on the diaphragm no longer needs a bearing plate.
Can they send someone to my house to get my bell housing that clean too?
Uryk makes great stuff and I’m sure this is a quality part however I wouldn’t be so anxious to replace something that’s been working reliably for decades, a known quantity. That someone made a bad batch of carbon bearings is not a reason to change the design, a bad batch of roller bearings is just as possible. I’d feel a more comfortable if the bearing used was not new but adapted from a known quantity.
pauls
OEM. It only locates the fork on the rod. There’s no torque applied to this pin unlike the 120-150 and Mk VII and possibly others. It’s a bit backwards as the bell housing is the bearing surface rather than the much cheaper fork. I’d rather have seen them put this pin on either side of the bell housing and let the fork take the wear.
I don’t think anyone is claiming that it is…as long as the consumer can be assured that the quality issues have been resolved, and won’t come back next year. However, the track-record for our current crop of aftermarket suppliers doesn’t bode well in that regard.
Yes, Sachs or someone like them could pump out a bad batch of roller bearings, but I think the chances of that happening are orders of magnitude lower than some no-name factory in a 3rd world country that is currently producing our carbon bearings.
From what I’ve seen of his work, Uryk appears to be “an Engineer’s engineer”. Embarking on designing a new roller bearing when there are about a billion high-quality options out there that can be adapted would be a fool’s errand. I’d be willing to bet a fair amount of money that the bearing is an existing part that has been adapted.
I still have my 4.2 bell housing with the GTJ roller bearing collar and ball bearing TOB. I replaced it when I installed my Medatronic 5 spd. I put it on the sale page a few times. It worked really well for the 20 years that it was used. It used a turned collar that is mated with the bell housing. The for is somewhat modified to allow the bearing to slide on the collar and stay centered.
In all honesty, this isn’t rocket-surgery, but I’ve seen some pretty bad solutions out there to these issues. The MG guys are so spooked by these carbon bearing failures that many of them are installing roller bearings that have no centering feature whatsoever. As a result, the bearing does some goofy combination of skidding and spinning. From an engineering perspective, that’s a recipe for a mess!
I hear that sort of reaction from a lot of people who are new to the Brit car hobby.
My 1964 Land Rover has quite a beautifully engineered clutch actuation system that included a concentric roller bearing. As far as I’m aware, that design dates back to the earliest Land Rovers of the late 40’s…a truck that was designed to be a farm implement!
Ben’s comment is 100% on the money regarding the bearing’s ability to self centre.
Jaguar manufactured the bell housing with throwout bearing assembly knowing that the throwout bearing need not be perfectly centered. Ccentering the graphite throwout bearing to the crankshaft center axis was not critical as the graphite can via lubricated slippage.
But if you put a non-graphite throwout bearing in, it must have some sort of centering ability or there will be induced wear.
I have never had a problem with the graphite and it has never worn out before the clutch disc. So I will stick with it
It definitely should remain centered. I wish I could tell from the image how that is accomplished. It’s still pivoting on the end of the fork, thus swinging in an arc. There must be some kind of magic occurring behind the bearing that we can’t see.
It’s not so much that the carbon bearing doesn’t need to be centered, it’s that it’s designed to almost NEVER be centered.
The carbon bearing moves in an arc, and therefore, sort of “wipes” itself across the face of the mating plate.
Theoretically, there is only one point in its throw where it can ever be centered, but given manufacturing tolerances, that likely never happens on most OE set-ups.
It appears to be riding axially on a collar, like all OE roller bearings do. There must be a degree of freedom where it mates to the fork…this would be pretty easy to accomplish.
Their post made a point of referring to it as a “concentric” bearing.
Only a sample of 1 but the only throw out bearing failure I ever had was a roller. That said I was never in love with the carbon type but the fact is it never failed me or wore out during my life with one.
pauls
As I mentioned, there was a period (actually more than a batch) of bad MG bearings that the suppliers (at least Moss Motors) now own up to.
So yeah, I’ve owned and driven MGBs for 25 years, and never had a carbon bearing failure, but my confidence in the ones that are currently on the supplier shelves is pretty low to the point where I’ve bought a few NOS bearings on eBay for my personal stockpile.
